Stuart Stevenson wrote: > Can I effectively bypass the SCR tuning by increasing the gain a > lot (much past what the motor can handle) and using the tuning in EMC > to control the motor. Could this turn the SCR into a dumb amp. > thanks > Stuart
What is the source of the feedback? Is it the motor shaft or table encoder? From my readings on this subject, it is best for the motor to have it's own loop - and then if you add a table feed back, it would be done as a outer PID loop - using only the 'I' of PID. I've also thought that the right way to do this would be to update the backlash every time the motion reverses so as the ball-screws warm up, the backlash numbers stay up to date. Then the net motion would be fed to the nested loop. To take this to the extreme, you could also feed in the force (calculated from the motor current) and have different backlash numbers depending on how hard the motor is pushing. I haven't done any of this yet, but from what I've read, it should be possible to have EMC2 do all of the control work - nested PID loops - backlash correction. I haven't seen where anyone has an actual system doing this? One point of view is that the controller should be as simple as possible and EMC2 would just tell the controller where to go (KISS). The other take on this is that Linux is stable enough that there shouldn't be any problem with it running the whole show - and if it is doing everything, extreme tweaking is possible. On Windoze, (or a boxes with nasty routines in the BIOS that interrupt realtime activities) it is best to go with KISS. On the other hand, Linux is quite stable, tweaking is fun, and moving the smarts to EMC should further reduce the cost of the electronics. My only concern is that most folks are running Ubuntu, which is rather bleeding edge for a motion control platform - I would rather see this on a Debian-stable distribution, where things don't change as often. -------------------------------------------------------------------------------- Karl Schmidt EMail [EMAIL PROTECTED] Transtronics, Inc. WEB http://xtronics.com 3209 West 9th Street Ph (785) 841-3089 Lawrence, KS 66049 FAX (785) 841-0434 Experience is something I never get, until just after I needed it. -------------------------------------------------------------------------------- ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
